<b>Objective: </b>To investigate effects of maternal diabetes
and metformin treatment on metabolic newborn screening (NBS) results of infants
born to mothers with hyperglycemia during pregnancy
<p><b>Research Design and Methods: </b> Retrospective
case-control study. NBS results of infants born to mothers treated with
metformin for hyperglycaemia during pregnancy were compared with diet-treated
diabetes and matched normal controls. Exclusions: maternal type 1 diabetes, major
fetal anomalies, incomplete infant data. Inclusions: maternal hyperglycemia in
pregnancy treated with diet alone or diet plus metformin. Results from the New
South Wales NBSP (dried infant bloodspot sample, 24-72 hours after birth) for
25 routinely studied analytes, were measured using mass spectrometry. Data from
metformin-exposed and control infants were compared using non-parametric
methods and multiples of the median for each analyte. </p>
<p><b>Results: </b>574 cases were compared with 952
diet-treated diabetes cases and 979 controls. Metformin-exposed infants had
shorter gestational age (266 days ±7 vs 272±10±34vs 274 ±9 ) (p= <0.001) and lower birth weights
(3.28 kg ±0.51vs 3.29±0.49 ±0.52 vs
3.33±0.43) (p=0.008). Short, medium and one long-chain acylcarntine
(tetradecanoylcarnitine; C14) concentrations were higher in the metformin
exposed group compared to normal controls. Comparison with diet-treated diabetes
controls (to eliminate confounding by hyperglycemia) continued to show raised butyrylcarntine
(C4), isovalerylcarnitine (C5), glutarylcarnitine (C5D) in the
metformin-exposed group. There was no evidence of vitamin B12 deficiency (low
methionine, elevated propionylcarnitine; C3) in metformin-exposed infants. All results were within normal population
limits. </p>
<p><b>Conclusions: </b>We have identified subtle (non-pathological)
changes in neonatal metabolism which represents a signature effect of fetal
metformin exposure. </p>
Is maternal diabetes associated with COVID-19 disease progression in pregnancy?